I’m researching a custom Hupmobile that raced the Bonneville Salt Flats in 1935, 1936, and 1937. Here’s a photo I’ve created of the partially restored car rendered over a picture of the salt flats along with a picture of the car in 1937.

My father is restoring the Hupp and I’m hoping folks at the H.A.M.B. can help me find out more about the car. Here’s what I know so far:

The “Bonneville Hupp” was originally owned and built by Dr. Norbert Knoch, a physician from Denver, Colorado who typifies the racing enthusiasm that took hold of America despite the hardships of the Great Depression.

Knoch’s pursuit of speed was so relentless that he ended up working with executives and engineers not only at Hupmobile, but also at the Ethyl Gasoline Company, the Gambill Motor Company, Kendall Refining, Schwitzer Cummins, Ray Day Piston, and Firestone Tire.

Knoch also recruited future racing legends like Bill Kenz to his team, traded racing parts with Babe Stapp, and acted as race physician to David Abbott "Ab" Jenkins on his record-setting runs in 1937.

Dr. Knoch bought his Hupmobile Model H right off the showroom floor at the Hupmobile dealership in Denver, Colorado. We’ve even been able to obtain the original title.

Originally a 4-door touring car, the Hupp was brought to the Niederhut Carriage Company, a carriage company local to Denver, for the construction of a custom boat-tailed body.

The body was designed by Ernest H. "Ernie" Niederhut, son of Henry E. Niederhut, who founded the company (originally Niederhut Bros.), with his brother William G. Niederhut, in 1892. According to one document we received with the car, the fenders on the Bonneville Hupp inspired the fenders on the Mormon Meteor, as they cut air resistance and kept salt from spraying the driver.

Once the body of the car was complete, Dr. Knoch set about trying to find way to modify his Hupp to reach the fastest speeds possible. He started this by writing to Hupmobile about how he might raise the compression ratio of the engine to 7.5:1.

These early letters from Dr. Knoch to the Hupmobile Motor Car Corporation seem to have been met with confusion, the executives seemingly unaware that Knoch was intending to race at Bonneville. They refer to the car’s performance “at Denver altitude,” referencing the doctor’s home town, and that Knoch’s questions about potentially using multiple carburetors made little sense for a “pleasure car.” Was Knoch being coy as to what he was hoping to do with his Model H? Perhaps that was the case as the Hupp executives may have assumed was still being used as a touring car by a simple country doctor.

The next challenge was raising the octane of the fuel used in the Hupp, an especially difficult task in an era before modern gasoline. So Dr. Knoch sought out fuel additives, such as Ethyl Fluid, developed by the Ethyl Gasoline Company. However, Ethyl executives steered Knoch toward the use of Benzol, noting that a 20% benzol-to-gasoline ratio would achieve about 83 octane. Knoch proposed using 90% benzol.

And so he did, and seemingly to great effect. Knoch and his team developed what one Ethyl Gasoline executive called “an ingenious method of operating your cars by bleeding benzol into the carburetor.” The benzol tank that fed this bleed is still part of the car today.

Knoch also wrote to Hupmobile to inquire about twin carburetors, probably seeking to emulate the multi-carb approach of what was probably the world’s most famous Hubmobile, the “Hupp Comet.”

The Comet was a race car driven by the famous Russell Snowberger. Before driving the Comet, Snowberger entered his own car, a Studebaker, into the Indianapolis 500 and finished 5th in 1931.

This impressive upstart performance caught the attention of executives at Hupmobile, who wanted to promote their cars through involvement in the growing phenomenon of Indy Racing. Hupmobile coaxed Snowberger to pull the Studebaker motor out of his race car and install a Hupmobile H engine, of his design, to race at Indy for the Hupp Corporation. His car was then dubbed the “Hupp Comet.”

But with the deepening of the Great Depression, Hupmobile’s Indianapolis racing endeavors were short-lived. At the end of the 1932 season Russell Snowberger decided to go his own way and returned the engine and all Hupmobile-related parts back to the company.

But the executive at Hupmobile were not about to let a good engine go to waste. Instead, they could sell the engine to Dr. Knoch, this new sort of upstart in Colorado. It would allow them to recoup some of their investment in the Indy team, but more interestingly it would allows them to foster what was essentially an unofficial Hupp racing team at Bonneville.

This was especially interesting for the cash-strapped Hupmobile Motor Car Corporation as racing at Bonneville didn’t face the pressures of Indy, with its regular schedule of races and the pressure that go with them. Racing at the Salt Flats was less about drivers racing against each other, and more about racing against the bounds of what current engineering and technology made possible.

By helping Knoch, the folks at Hupmobile had a race team that was self-financing, whose losses would go unnoticed, but whose potential wins would give them the headlines they needed to sell cars. This tiny downside, big potential upside logic lead executives like F. J. Snyder at Hupmobile to consistently entertain Dr. Knoch’s continuing stream of requests for special parts and engineering advice.

So in 1933 the Hupp Comet motor was sold to Dr. Knoch and installed in the Bonneville Hupp. He then set about putting the motor to use, and of course, writing more letters to Hupp. He now made requests for replacement gaskets from the Victor Gasket Company, who had supplied gaskets for Snowberger's race team. Eventually, he found them, care of the Gambill Motor Company, a Hupp distributor.

Finally, 1935 saw the first run of the Bonneville Hupp at the Salt Flats. According to an extensive write-up in the August 1977 edition of Cars & Parts, later republished in the Hupp Herald, Dr. Knoch himself drove the car to a speed of 136 mph. Photographs taken that day show Augie Duesenberg’s dog sitting in the car and it is believed that Augie himself timed the car.

But Duesenberg wasn’t the only connection Knoch made with Bonneville royalty in 1935. The Bonneville Hupp was prepared for racing the salt flats by Bill Kenz, who was just beginning what would become one of the most illustrious careers in racing. Kenz went on to partner with Roy Leslie, and together the two established a career in drag racing, midget racing, and a dominating presence at Bonneville. Their “Odd Rod” ran at over 140mph on the salt flats in 1949 and their later “777 Streamliner,” powered by three flathead eight engines, posted a speed of 261.81mph in 1956.

The excitement of the 1935 run and the association with famed Duesenberg brothers pushed Knoch to go even faster. He was finally doing what he wanted to be doing, racing in big leagues. As he began rethinking the car’s design in 1936, Dr. Knoch sought out new gear ratios for the Bonneville Hupp.

Gaskets were then upgraded, supplied by the McCord Radiator Company, who produced copper-reinforced gaskets that would hold up better when exposed to high temperatures.

The car was run at Bonneville again in 1937. We have several photos from this trip to Bonneville.

After this run, it seemed that the new axle ratio became a cause for concern. The 3.25:1 modified gears provided by Automotive Gear Works of Richmond, Indiana were overheating when the Hupp ran at high speeds over long periods of time.

In May of 1937, Knoch sought to resolve the overheating problem by seeking advice from Automotive Gear Works, the same company who produced the axle gearing. They recommended using Castor Oil, rather than using a lead-based lubricant. Knoch also sought advice from Kendall Refining, who were happy to recommend several of their own products.

In September of the same year, Knoch became part of Bonneville history, but perhaps not in the way that he imagined. It was at that time that David Abbot “Ab” Jenkins set at 24-hour world speed record of 157.27mph. Dr. Knoch tended to Jenkins, who was injured part-way through the run, having a piece of metal embedded in his arm, which Knoch is quoted as saying barely missed one of Ab’s major blood vessels. Brownie Carslake of Firestone Tire would later thank Dr. Knoch for his assistance, writing “none of us will ever forget how readily you stepped in and the timely assistance you gave when assistance was really needed.”

After 24-hour record run, Dr. Knoch became friends with Babe Stapp, Ab’s backup driver, who sent not only advice but also parts to Dr. Knoch, including a steering gear and possibly a flexible wheel.

Throughout 1938 and 1939 Dr. Knoch appears to have continued his pursuit for speed. He wrote to Schwitzer Cummins about supercharges and was met with some of the skepticism that he was met with in his early letters to Hupp. Lee Oldfiend, a Consulting Engineer at Cummins, reacted to Dr. Knoch’s proposed configuration of a supercharger by writing “such a combination could not be very useful except at speeds close to the peak” and “we should like to discourage you with this project.” Mr. Oldfield also didn’t contact “Mr. Duesenberg” about the proposed configuration, as Dr. Knoch had suggested. Oldfield didn’t realize he was writing to the man who quite possibly saved Ab Jenkins life!

The letter writing went on and Dr. Knoch received replies from American Bosch regarding a magneto and to Air Associates regarding their Anilol fuel additive. Interestingly, Milton Chapel of Air Associates claimed that hundreds of race car drivers had adopted Anilol from its introduction to the racing community in October of 1938 to the time of his writing to Dr. Knoch, which was only seven months later.

We don’t know if the supercharger was ever added to the Bonneville Hupp or if Dr. Knoch ran the car with alternate fuels or additives after 1938. Our records drop off after those dates other than the chain of ownership. We know the car was eventually sold to Don Crites, also of Denver. From there is was sold to Frank Kleptz of Terre Haute, Indiana.

The Bonneville Hupp stayed in Frank’s possession until recently when John Snowberger, Russell Snowberger’s son, purchased the racer in order to turn back the hands of time and restore his father’s 1932 Hupp Comet.

My dad acquired the body and chassis of the 1930 Hupmobile Bonneville from John Snowberger and is currently restoring it to its 1932 racing configuration, including an original Model H engine.

We are hoping the H.A.M.B. members can help us find anything related to the car, such as timing records, photos at the salt flats, articles that have been written about the car, or anything mentioning Dr. Knoch’s association with Ab Jenkins and the Mormon Meteor runs in 1937. We’re also hoping to find someone in the Denver area who might be willing to do some local digging for us.

Thanks so much for the positive feedback everyone. Please share this post with classic racing fans you know. Experience shows that additional information about cars like this one can found in the most unexpected places, so the more we share this with folks in the community, the more likely we are to find that old photo or letter related to the car.

Also, does anyone know of books on the Duesenbergs that might talk about their activities at Bonneville?

I've found a clipping from the "Automobiles" section of the Omaha Daily Bee from 1909 that mentions Dr. Knoch accompanying a Denver businessman and his family on a cross-country trip to New York in a Peerless automobile.

In 1909 traveling cross-country via car had to be quite an adventure, so much so that it was worth publishing in the paper!

@s55mercury66 I guess I wouldn't know how to go about doing that. Are there surviving members of the family who preserve photos from Ab's racing career? I want to be respectful of their time, but if they are amenable to being asked questions about this sort of thing, I'd really appreciate speaking with them.

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@Cord Blomquist , I would imagine the Jenkins family would have a lot of photos, but getting in touch with them may require some searching. Ab's son Marvin was involved in a lot of his father's later attempts, and was also involved with the Novi, through his friendship with the Winfield brothers. The Salt Lake Tribune may have some photos in their archives also. Ab Jenkins was a driving force behind the salt flats becoming the record setting venue it was, and still is today. I do not personallyknow any members of the family, but I would not be afraid to reach and try to contact them.

@alsancle I think Ab had more resources than Dr. Knoch, given that he was working directly with the Duesenbergs. As far as I know, the Hupp Comet had one engine and it's back with John Snowberger. I'm trusting that John only bought the Bonneville Hupp because it was the only way to get the engine back. All that said, I have no definitive record that says there was only one engine built.

Does anyone know if Ab Jenkin's correspondence is kept in a museum where I could request copies. Similarly, would the ACD museum have copies of Augie Duesenberg's letters? I'm trying to figure out the next threads to pull on this investigation. I feel like I'm in an episode of Cold Case!